The present invention relates to a manipulator and a manipulator system, each having an operating part mechanically connected to a moving part.
So far there has been a manipulator disclosed in JP(A) 2009-201607, wherein one end of a wire inserted through a hollow shaft is routed around a driving pulley and the other end is done around a driven pulley for power transmission.
With the manipulator disclosed in JP(A) 2009-201607, however, there is no power transmission ensured when no sufficient tension is applied to the wire routed around and between the driving pulley and the driven pulley. It is thus required to adjust the tension of the wire for rapid and precise power transmission.
FIGS. 22A-22c are illustrative in schematic of one conventional manipulator.
As shown in FIG. 22A, a wire 140 routed around and between an operating-side pulley 122 and a moving-side pulley 132 of a manipulator 110 in a neutral state has often a small slack 100. The manipulator of JP(A) 2009-201607 is previously cleared of such a small wire slack by adjustment of the wire tension.
On the other hand, such as when an operator (not shown) rotates a handle 121 from a neutral state of FIG. 22A in a direction indicated by an arrow A1, there are possible elongation of a wire 141 and friction or the like due to contact of a wire 140 with a guide member that receives the wire 140 in association with rotation of the handle 121 and operating-side pulley 122 in the direction indicated by the arrow A1, resulting in a dynamic slack 101 as shown in FIG. 22B.
Thereafter, when the handle 121 is reversed in a direction indicated by an arrow A2 as shown in FIGS. 22B and 22C, there is no tensile force transmitted to the moving-side pulley 132 until the dynamic slack 101 shown in FIG. 22B is taken out of the wire 140 with the result that the moving member 131 is unlikely to be actuated even with the operation of the handle 121 as shown in FIG. 22C.
The manipulator of JP(A) 2009-201607 does not clear such dynamic slack. Such a dynamic slack remains more or less even though that slack is previously cleared as is the case with such a manipulator as described in JP(A) 2009-201607. Even though the wire is previously cleared of any slack with the application of strong tension to it so as to prevent occurrence of any dynamic slack, another dynamic slack may not only occur from friction of the wire 140 with a wire guide member but also the wire may break off upon receipt of too strong a force.
A manipulator disclosed in U.S. Pat. No. 6,565,554 is designed to add a load determined by a friction compensation signal to an actuator for compensation thereby improving on operability. However, the manipulator described in U.S. Pat. No. 6,565,554 cannot gain control in association with state or performance fluctuations because compensation is made at a constant value.
With the problem in mind, it is an object of the invention to provide a manipulator and a manipulator system wherein any dynamic surplus is so rapidly removed that a moving part is rapidly actuated in association with the operation of an operating part.